Patents by Inventor James A. Braatz

James A. Braatz has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5169720
    Abstract: Polymer-coated medical and laboratory devices are disclosed which are characterized by their biocompatibility and resistance to nonspecific protein adsorption. The polyurea-polyurethane coatings of this invention are prepared from high molecular weight isocyanate end-capped prepolymers substantially or exclusively comprised of ethylene oxide units. At least 75%, preferably at least 90%, of the prepolymer units are oxyethylene-based diols or polyols having molecular weights of about 7000-30,000, with essentially all of the hydroxyl groups capped with polyisocyanate prior to formation of the hydrated polymer coating.
    Type: Grant
    Filed: March 6, 1991
    Date of Patent: December 8, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Aaron H. Heifetz, Clifton L. Kehr, Richard A. Wolfe
  • Patent number: 5135866
    Abstract: This nutrient medium is very effective for the serum-free or serum-protein-free culture of various animal cells, in both high and low density culture. Serum proteins have been replaced with non-protein-based cell growth enhancers and a non-serum derived protein supplement. The non-protein growth enhancer is a modified or derivatized polyurethane prepolymer of polymer and preferably is a sulfhydryl derivative of polyurethane. The protein supplement may be insulin, an insulin analog or an insulin-like growth factor.
    Type: Grant
    Filed: March 3, 1989
    Date of Patent: August 4, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Aaron H. Heifetz, James A. Braatz
  • Patent number: 5091176
    Abstract: Biocompatible polymers derived from isocyanate-capped high molecular weight triols and higher polyols are covalently linked to drugs. These polymer-modified drugs have one or more of the following advantages over the unmodified drug: reduction of immunogenicity of the drug, increased circulating half-life of the drug due to longer residence time in circulation, ability to administer multiple drugs together, and enhanced potency of the drug.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: February 25, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Aaron H. Heifetz
  • Patent number: 5039458
    Abstract: A method of preparing a hydrophilic, biocompatible contact lens characterized by a surface which resists nonspecific protein adsorption. The method involves forming a prepolymer, at least 75% of which are oxyethylene-based diols and polyols having molecular weights of about 7000 to about 30,000. The prepolymer is subsequently gelled and hydrated to produce a hydrated polyurea-polyurethane polymer gel. The hydrated polymer gel is used to obtain a contact lens which resists nonspecific protein adsorption. Preferably, the contact lens are prepared by molding the prepolymer into a contact lens mold, prior to polymerization, to achieve the desired lens shape.
    Type: Grant
    Filed: November 7, 1989
    Date of Patent: August 13, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Clifton L. Kehr
  • Patent number: 4999298
    Abstract: The cell culturing system of the present invention includes a tubular membrane, e.g. hollow fiber, cartridge. Provision is made for the continuous circulation of a nutrient-containing medium through the tube side of the cartridge by pumping the nutrient-containing medium in an endless loop. The cells to be cultured are placed within the cartridge on the shell side where the desired extracellular products are accumulated. Nutrients are assimilated into the cell culture through the semipermeable tubular membranes and waste products are removed by passing through the semipermeable membranes into the recirculating nutrient-containing medium. Within the endless loop are located a circulating pump, an oxygenator and a pH probe. The system additionally includes a variable delivery feed pump for continuously injecting fresh nutrient-containing solution into the loop, which feed pump is operated at a rate responsive to the measured pH.
    Type: Grant
    Filed: April 27, 1988
    Date of Patent: March 12, 1991
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Richard A. Wolfe, Aaron H. Heifetz, James A. Braatz, David M. Donofrio
  • Patent number: 4940737
    Abstract: A class of modified hydrophilic prepolymers and polymers is disclosed which are characterized by their specific reactivity. Isocyanate-capped oxyethylene-based prepolymers are modified by reacting with a compound having an isocyanate-reactive group which is a sulfhydryl group, an amino group, a hydroxyl group or a carboxyl group, and a non-isocyanate-reactive group, in quantities sufficient to modify at least a portion of the isocyanate groups of the prepolymer. Where said first functional group is an amino group contained in a diamine or polyamine compound or is a carboxyl group, the modifying compound is present in quantities sufficient to modify all or substantially all of the isocyanate groups of the prepolymer.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: July 10, 1990
    Assignee: W. R. Grace & Co.-Conn
    Inventors: James A. Braatz, Aaron H. Heifetz, Richard A. Wolfe, Narender P. Luthra
  • Patent number: 4929706
    Abstract: Modified hydrophilic prepolymers and polymers are disclosed wherein the prepolymers and polymers are characterized by cell growth enhancement, and, in some instances, antibody production stimulation. Isocyanate-capped oxyethylene-based prepolymers are modified by reaction with a compound having at least one isocyanate (NCO) reactive group. Preferably, the NCO reactive group is a sulfhydryl group, an amino group or a carboxyl group, in quantities sufficient to modify at least a portion of the isocyanate groups of the prepolymer. The prepolymer and polymer also express a free functional group, preferably an amino, sulfonic acid or a sulfhydryl. When the free functional group is sulfhydryl or sulfonic acid, antibody production stimulation, as well as cell growth enhancement, is observed.
    Type: Grant
    Filed: March 3, 1989
    Date of Patent: May 29, 1990
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: Aaron H. Heifetz, Richard A. Wolfe, James A. Braatz, Narender P. Luthra
  • Patent number: 4886866
    Abstract: Hydrophilic polymeric soft contact lenses which are characterized by their biocompatibility and resistance to nonspecific protein adsorption. At least 75%, preferably at least 80%, of the prepolymers from which the lenses are prepared are isocyanate-capped oxyethylene-based diols or polyols having molecular weight of about 7000-30,000. Essentially all of the hydroxyl groups of the diols or polyols are capped with polyisocyanate prior to formation of the hydrated polymer of which the contact lenses are made.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: December 12, 1989
    Assignee: W. R. Grace & Co.-Conn.
    Inventors: James A. Braatz, Clifton L. Kehr
  • Patent number: 4514506
    Abstract: The invention comprises a method for the purification of a human lung tumor-associated antigen (hLTAA) specific to human lung tumors of diverse histological characteristics; serum levels of hLTAA correlate with lung tumor incidence, and appear to usefully discriminate between various stages of the malignancies. The invention further comprises an immunoassay predicated on purified hLTAA for the detection and quantitative determination of hLTAA in biological fluids, particularly blood serum, and diagnostic systems for clinical immunoassay procedures.
    Type: Grant
    Filed: January 28, 1983
    Date of Patent: April 30, 1985
    Assignee: The Government of the United States as represented by the Secretary of the Department of Health and Human Services
    Inventors: James A. Braatz, Kenneth R. McIntire, Gerald L. Princler